The present invention relates to an assembly of auxiliary and main electronic scanning antennas and to a radar incorporating such an assembly.
An electronic scanning antenna comprises in per se known manner elementary radiation sources and for each of these a phase shift circuit, whose phase angle can be adjusted by means of a control circuit. The modification of the phase angles changes the pointing direction of the antenna.
When a radar is equipped with an anti-jamming device, in general an adequate number of auxiliary antennas is used to ensure that each of them is pointed in the direction of a jamming station. In this case, the signals from these auxiliary antennas are mixed after their amplitude and phase have been appropriately adapted to those from the main antenna in order to cancel out the signals from the various jamming stations. This solution involves the use of a larger number of auxiliary antennas, which must be equal to the number of jamming stations. Therefore, the cost and overall dimensions of such an electronic scanning antenna assembly are very considerable.